This invention relates to bags, and in particular to resealable freezer storage bags. Various types of resealable bags exist, but these bags have closures which are either difficult and expensive to manufacture or cumbersome to use or have fasteners which are a discrete component and therefore can easily become lost.
For example, one common freezer bag closure consists of a zipper type closure. This type of closure requires special machinery to manufacture the closure and therefore is quite complicated and expensive to produce.
Another common type of freezer bag is described in U.S Pat. No. 2,849,171 to O'Brien. This fastener consists of a plastic or metal tie member which can be adjustably fastened around a twisted end of the bag to reseal the bag after opening. This type of fastener, however, is not integral to the bag structure and can easily be lost. Another type of discrete resealing device is a removable lock tab, such as disclosed in U.S. Pat. No. 4,753,539 to Collie et al.
Other types of resealable bags having integral closures are cumbersome to use. One example is the resealable bag described in U.S. Pat. No. 4,008,851 to Hirsch. The Hirsch bag contains a strip of adhesive material which is fixably attached at one end to the bag and removably attached along the remaining portions of the strip. To close the bag, the removable portion of the strip is removed from the bag. The bag is then twisted in the region near the adhesive strip and the twisted bag end is then fastened by looping the free end of the adhesive strip around the twisted portion and resecuring the strip to the bag.
Such a closure system is cumbersome to use for several reasons. First, the adhesive strip contains adhesive along the detachable portion. This detachable portion is frequently handled by the bag user, whose hands/fingers may become sticky from contact with the adhesive strip. In addition, the user's frequent contact with the strip may contaminate or remove significant amounts of the adhesive such that the closure can no longer effectively function. Second, the bag can only be effectively resealed in the region of the adhesive strip. If only a portion of the bag contents located above the strip are removed, the bag cannot be effectively sealed by this closure since the bag cannot be twisted in the region of the strip due to the remaining bag contents. Therefore, the strip is normally located in a region close to the top portion of the bag. However, as the bag contents dwindle, a larger volume of air will be trapped between the seal and the remaining contents. This volume of air reduces the freshness of remaining items stored in the bag.